In a large mixing bowl, combine chopped carrots, parsnips, Yukon Gold potatoes, and red onion. Drizzle with olive oil, salt, and pepper, toss until evenly coated, and spread in a single layer in a baking dish.
In another bowl, whisk together Dijon mustard, heavy cream, honey, garlic powder, onion powder, dried thyme, paprika, salt, and pepper until smooth.
Pat chicken thighs dry. Arrange the thighs on top of the prepared vegetables in the baking dish. Brush the Dijon cream sauce over each chicken piece.
Place the dish in the oven and bake for 40-45 minutes until the chicken is golden brown and reaches an internal temperature of 165ยฐF (74ยฐC).
Optional: Switch to broil for the last 2-3 minutes for a crispy crust.
Let the chicken rest for 5 minutes before serving with the roasted root vegetables and sauce.
Notes
For a crispier skin, you can sear the chicken thighs skin-side down in a hot pan before placing them in the baking dish.
Adjust the amount of honey to your preference for sweetness.
Feel free to substitute other root vegetables like sweet potatoes or turnips.